Cardiac mapping system and method with integrated navigation mode

Abstract

Methods and systems for collecting and presenting cardiac medical information to a physician using a medical device. The method includes receiving impedance-based position data from the electrode. A first navigation pattern for visualizing the medical device is generated using the impedance-based position data. Magnetic-based position data is received from a magnetic sensor. A second navigation pattern for visualizing the medical device is generated using the magnetism-based position data. It is determined whether the medical device is within the magnetic motion frame generated by the magnetic field generator. One or more of the magnetic-based position data and the impedance-based position data are used to determine whether the medical device is within the magnetic motion frame. The method includes outputting a first navigation mode to a display when the medical device is outside the magnetic motion frame; and outputting a second navigation mode to the display when the medical device is inside the magnetic motion frame.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application 63 / 530,758, filed August 4, 2023, entitled “CARDIAC MAPPING SYSTEMS ANDMETHODS WITH INTEGRATED NAVIGATION MODES”, the entire contents of which are incorporated herein by reference. Background Technology

[0003] This disclosure generally relates to medical positioning system devices, systems, and methods for positioning intra-body catheters by selecting between impedance-based navigation and magnetism-based navigation.

[0004] Medical positioning systems (MPS), such as impedance-based and magneto-based systems, are used to determine the location and / or orientation of medical devices within a patient's body. Other methods for monitoring the location / orientation of medical devices within the body include the use of fluorescence fluoroscopy radiation (e.g., X-ray radiation). However, both impedance-based and magneto-based navigation do not require exposure to X-ray radiation and are therefore preferred in certain applications.

[0005] A typical electroanatomical 3D navigation system comprises a 2D image acquisition system (e.g., ultrasound or low-fluorescence fluoroscopy), a medical positioning system (MPS) (i.e., a position and orientation detection system), and an image processing system. The imaging system reconstructs a 3D image from all recorded 2D images. The system displays a series of such 3D images, synchronized with real-time readings of the organ's temporal signals, thus providing real-time visualization of the organ being examined. The physician can insert minimally invasive surgical instruments (e.g., sensor-enabled catheters) into the patient's body. The system detects the position and orientation of the MPS sensors mounted on the surgical instruments and overlays their representation onto the currently displayed 3D image. Therefore, the electroanatomical 3D navigation system enables the physician to visualize the surgical instruments relative to the organ being examined, thereby assisting the physician in performing medical procedures. Summary of the Invention

[0006] According to a first aspect of the invention, a method for collecting cardiac medical information using a medical device and presenting it to a physician includes: receiving impedance-based position data from electrodes; generating a first navigation pattern (or "impedance-based navigation pattern") for visualizing the medical device using the impedance-based position data; receiving magnetic-based position data from a magnetic sensor; generating a second navigation pattern (or "magnetic-based navigation pattern") for visualizing the medical device using the magnetic-based position data; determining whether the medical device is within a magnetic motion frame generated by a magnetic field generator; and determining whether the medical device is within the magnetic motion frame using one or more of the magnetic-based position data and the impedance-based position data. The method includes outputting the first navigation pattern to a display when the medical device is outside the magnetic motion frame and outputting the second navigation pattern to the display when the medical device is inside the magnetic motion frame.

[0007] The method may also include switching between a first navigation mode and a second navigation mode when the medical device moves across the boundary of the magnetic motion frame.

[0008] Generating a first navigation mode may include: receiving a first electrical signal measured by electrodes; analyzing the first electrical signal using an electronic control unit (ECU); and converting the first electrical signal into a first position point in an impedance-based coordinate system.

[0009] Generating a second navigation mode may include: receiving a second electrical signal generated by a magnetic sensor in response to an external magnetic field; analyzing the second electrical signal using an ECU; and converting the second electrical signal into a second position point in a magnetic-based coordinate system.

[0010] Determining whether a medical device is within a magnetic motion frame may include comparing a second position point of a magnetic sensor with the boundary of the magnetic motion frame. Alternatively, determining whether a medical device is within a magnetic motion frame may include comparing a first position point of an electrode with the boundary of the magnetic motion frame.

[0011] The method may further include determining whether the medical device is inside the patient's body, wherein when the medical device is outside the patient's body, neither the first navigation mode nor the second navigation mode is output to the display. Determining whether the medical device is inside the patient's body may include: driving an electrical signal through a first electrode; measuring a voltage signal on a second electrode; calculating a bipolar complex impedance using the measured voltage signal; and comparing the bipolar complex impedance with a threshold.

[0012] The transition between the first and second navigation modes can occur within a single study. The transition may include a model transformation. This model transformation could involve converting a first location point in an impedance-based coordinate system to a magnetically based coordinate system. The transition from the first to the second navigation mode within a single study can occur automatically when a magnetic sensor is detected in the magnetic motion frame. Alternatively, the physician can be prompted to transition from the first to the second navigation mode within a single study when a magnetic sensor is detected in the magnetic motion frame.

[0013] Regardless of whether the first or second navigation mode outputs to the display, both the first and second navigation modes can continuously and / or simultaneously calculate the magnetic sensor position and electrode position. The method may include a feedback loop to continuously determine whether the medical device is inside the patient's body and / or within the magnetic motion frame, and generate output accordingly.

[0014] The magnetic motion frame can be a cuboid defining a three-dimensional (3D) coordinate system, configured to enclose the patient's heart. Alternatively, the magnetic motion frame can be defined by other geometries and / or coordinate systems.

[0015] The output to the display in the second navigation mode may involve outputting magnetically based position and / or orientation data to the display. This output can provide a visual representation of the position and / or orientation of the medical device within the patient's body.

[0016] According to a second aspect of the invention, a medical imaging and navigation system includes a medical device, a pair of surface patch electrodes, a magnetic field generating component, a display, and a processor. The medical device includes device electrodes and a magnetic sensor. The surface patch electrode pair is positionable on a patient. The surface patch electrode pair is configured to generate an electric field within the patient's body. A first electrical signal is measured on the device electrodes due to the generated electric field. The magnetic field generating component is positioned near the patient. The magnetic field generating component generates a magnetic field within a magnetic motion frame. A second electrical signal is measured on the magnetic sensor due to the generated magnetic field. The processor receives the first electrical signal from the device electrodes and determines a first location point of the device electrodes based on the first electrical signal. The processor stores the first location point in a first dataset. The processor receives the second electrical signal from the magnetic sensor and determines a second location point of the magnetic sensor based on the second electrical signal. The processor stores the second location point in a second dataset. The processor uses the first dataset to construct an impedance-based mapping study and uses the second dataset to construct a magnetic-based mapping study. The processor selectively outputs either the impedance-based mapping study or the magnetic-based mapping study to the display based on the device's position within the patient's body. The processor is configured to switch from impedance-based calibration studies to magnetism-based calibration studies in a single study.

[0017] Impedance-based mapping studies include data collected from one or more sensors located on a medical device while operating in an impedance-based navigation mode, wherein the data may include tissue mapping (e.g., heart) based on impedance-based location data. Similarly, magneto-based mapping studies include data collected from one or more sensors located on a medical device while operating in a magneto-based navigation mode, wherein the data may include tissue mapping (e.g., heart) based on magneto-based location data.

[0018] The medical device can be any medical device, wherein location-based real-time data may be advantageous for procedures using the medical device. The medical device may include catheters, sheaths, guidewires, etc. Preferably, the medical device is a catheter.

[0019] The electrodes and / or magnetic sensors of this device may be collectively referred to as "sensors". The electrodes and magnetic sensors may be located at the distal end of the medical device. The magnetic sensor may include a magnetic coil.

[0020] Surface patch electrodes can generate electric / impedance fields within and around a patient's body. The surface patch electrodes can be positioned on and / or around the patient's body to generate an impedance-based coordinate system. The medical device may include device electrodes or electrode pairs to detect one or more characteristics of the electric field applied by the surface patch electrodes when the device electrodes are positioned within the patient's body. The electrodes / electrode pairs may be electrically / communically coupled to a processor.

[0021] A magnetic field generator can produce a low-intensity magnetic field within and around a patient's chest cavity (e.g., a region of interest during cardiac surgery). This low-intensity magnetic field can be defined in three-dimensional space as a specified magnetic motion frame (also known as a "region of interest"). The magnetic field generator may have three orthogonally arranged coils to create a magnetic field within the patient's body. The generator can be configured to control the strength, direction, and frequency of the field. The magnetic field generator can be located above, below, or at other suitable locations on the patient. The magnetic field generated by the coils, along with current or voltage measurements from one or more magnetic sensors, can be acquired.

[0022] The first position point based on the first electrical signal can be "impedance-based position estimation". The second position point based on the second electrical signal can be "magnetic field-based position estimation".

[0023] Surface-mount electrode pairs can be part of an impedance-based positioning system. A magnetic field generating component can be part of a magnetic field-based positioning system. Both the impedance-based and magnetic field-based positioning systems can be part of a medical positioning system. An electronic control unit (ECU) can be connected to the medical positioning system. The ECU provides methods for controlling the operation of various components of the system, including the medical device, the impedance-based positioning system, the switch of the electric field-based positioning system 136, and the magnetic field generator of the magnetic field-based positioning system. The ECU also provides methods for determining tissue geometry, tissue electrophysiological properties, and the position and orientation of the medical device relative to the tissue and the human body. The ECU can be configured to receive impedance-based and magnetic field-based positioning estimates associated with device electrodes or magnetic sensors. The ECU can be configured to determine whether to operate in a first navigation mode or a second navigation mode based on one or more inputs, including impedance-based position estimates and / or magnetic field-based position estimates. The ECU also provides a method for generating display signals for controlling the display.

[0024] When the medical device is inside the patient's body and outside the magnetic motion frame, the processor can be configured to output impedance-based calibration studies to the display.

[0025] When the medical device is inside the patient's body and within the magnetic motion frame, the processor can be configured to output magnetically based mapping studies to the display.

[0026] The processor can determine whether a medical device is inside a patient's body by measuring the bipolar complex impedance and comparing it to a threshold. This threshold can be a dynamic characteristic value established through a baseline step.

[0027] The display may be a user display. The user display may include a user interface that may be configured to allow physicians to select between a first navigation mode and a second navigation mode in a single study.

[0028] These and other examples and features of the apparatus, system, and method will be set forth, at least in part, in the following detailed description. This invention is intended to provide non-limiting examples of the subject matter and is not intended to provide an exclusive or exhaustive explanation. The following detailed description is included to provide further information about the system and method. Attached Figure Description

[0029] The contents of this written disclosure are further illustrated with reference to the following figures, in which:

[0030] Figure 1 This is a schematic diagram of an exemplary medical system for performing one or more diagnostic or treatment procedures, wherein the system includes a medical positioning system.

[0031] Figure 2A This is a schematic diagram of a sensor-enabled catheter inserted into a patient's body.

[0032] Figure 2B This is an enlarged view of the sensor-enabled conduit.

[0033] Figure 3 This is a flowchart of the method for selecting the navigation mode to display to the doctor.

[0034] Figure 4 It is a method to determine whether a catheter is inside a patient's body.

[0035] Figure 5A This is a flowchart of a method for determining whether a catheter is located within a magnetic motion frame.

[0036] Figure 5B This is a flowchart of a method for determining whether a catheter is located within a magnetic motion frame.

[0037] Figure 5C This is a flowchart of a method for determining whether a catheter is located within a magnetic motion frame. Detailed Implementation

[0038] This disclosure describes systems and methods for providing medical positioning. Specifically, the medical positioning system operates in an impedance-based navigation mode (also referred to as a "first navigation mode") and a magnetic-based navigation mode (also referred to as a "second navigation mode"). The medical positioning system selectively operates in either the impedance-based or magnetic-based navigation mode based on the determined location of the catheter.

[0039] Impedance-based navigation (or “positioning”) allows for immediate visualization of the location of a device with one or more electrodes inserted into a patient’s body. An impedance field (or electric field) is generated within the patient’s body by applying a pair (or more) of surface-patch electrodes to the body and driving an electric current through these electrodes. The catheter, including one or more electrodes, senses the impedance field and uses the measured response to the impedance field to determine the catheter’s location within the patient’s body. The advantage of impedance-based navigation is that the position of the electrodes is determined immediately upon insertion into the patient’s body, and therefore can be used to visualize the catheter at any location within the patient. Immediate visualization is advantageous because it allows the physician to visualize the catheter as it is advanced from the insertion point to the target area. However, impedance-based navigation also has some drawbacks. For example, the electric field (or impedance field) may fluctuate from patient to patient and / or may fluctuate within a single procedure due to variations in anatomical conditions. Furthermore, the electric field may be non-linear because bones, fat, and triglycerides within the body have high impedance, while body fluids and cell membranes have low impedance.

[0040] Magnetism-based navigation can also be used to determine the location and / or orientation of magnetic sensors within a patient's body and can provide higher accuracy than impedance-based navigation systems. However, magnetism-based navigation is typically only available within a specific region corresponding to a stable magnetic field. This region is sometimes referred to as the magnetic motion frame, where magnetic localization is highly accurate within the frame and less accurate outside it.

[0041] Magnetism-based navigation relies on a magnetic sensor located on the catheter to sense an external magnetic field. This magnetic field can be generated by a magnetic field generator assembly (e.g., located within the operating table). Typically, the magnetic field is optimized (e.g., stable, linear) within a specific three-dimensional space relative to the magnetic field generator assembly. The positioning of the magnetic field generator assembly relative to a target area associated with the patient (e.g., the heart) allows the magnetism-based navigation system to provide precise position and / or orientation information within a defined three-dimensional space or volume (referred to as a magnetic motion frame). A catheter including a magnetically enabled sensor is placed within the magnetic motion frame, and the magnetic field can transmit an electrical signal to this sensor. This electrical signal can be sent to a processor, which can calculate the position and orientation of the electrodes based on the received electrical signal.

[0042] Magnetic field-based navigation (or "positioning") provides precise location and / or orientation sensing within the magnetic motion frame, but may provide lower precision when the magnetic sensor is outside the frame. Therefore, magnetic-based navigation may be unusable (or potentially less accurate) when the catheter is first inserted into the body compared to impedance-based navigation, but may provide improved accuracy when the catheter is within the magnetic motion frame. Thus, it would be beneficial to utilize impedance-based navigation immediately after catheter insertion and switch to magnetic-based navigation once the catheter has entered the motion frame.

[0043] This disclosure describes a system and method that integrates impedance-based and magneto-based navigation modes, thereby allowing for automatic and / or on-demand (user-initiated) switching between impedance-based and magneto-based navigation modes within a single study. Therefore, the mapping / navigation system described herein enables immediate visualization after catheter insertion into the patient's body and provides stable, high-precision magneto-based navigation.

[0044] Figure 1A system schematic diagram of an exemplary medical system 100 for performing one or more diagnostic or treatment procedures is shown, wherein the system includes a medical positioning system 140. The medical system 100 may include a medical device 120 and a medical positioning system 140. The medical device 120 includes a handle 118 and a shaft 122 having a proximal end 124 and a distal end 126. The medical positioning system 140 includes an impedance-based positioning system 136 and a magnetic field-based positioning system 138. The impedance-based positioning system 136 includes a plurality of surface patch electrodes 134 attached to the skin of a patient 160, a switch 148, and an AC power supply 146 connected to the plurality of surface patch electrodes 134 via the switch 148. The magnetic field-based positioning system 138 includes a magnetic field generator 130 positioned near the patient, the magnetic field generator being configured to generate a magnetic field in an area surrounding the patient, particularly in an area designated as a magnetic motion frame 132. An electronic control unit (ECU) is connected to the medical positioning system 140 and configured to receive impedance-based and magneto-based positioning estimates associated with one or more sensors located at the distal end 126 of the medical device 120. In some embodiments, the ECU 144 determines whether to operate in an impedance-based mode (where the catheter position displayed via the display 142 is based on impedance-based measurements) or a magneto-based mode (where the catheter position displayed via the display 142 is based on magneto-based measurements) based on one or more inputs, including, in some embodiments, impedance-based and / or magneto-based positioning estimates. Operation in impedance-based mode does not preclude the use of inputs from other navigation methods. The impedance-based mode can therefore be referred to as the impedance-based master mode, where impedance data is dominant in determining the location of the medical device. Similarly, operation in magneto-based mode does not preclude the use of inputs from other navigation methods, including, for example, impedance-based navigation. The magneto-based mode can therefore be referred to as the magneto-based master mode, where magnetic data is dominant in determining the location of the medical device.

[0045] like Figure 1 As shown, medical device 120 may include elongated medical devices, such as catheters or sheaths, for example. For ease of illustration and clarity, medical device 120 in the following description includes catheters (e.g., catheter 120). It should be understood, however, that this disclosure is not intended to limit this particular medical device, but rather that the medical device may include other medical devices, such as, but not limited to, sheaths, guidewires, etc. Medical device 120 may be any medical device, wherein location-based real-time data may be advantageous for procedures using the medical device.

[0046] Distal end 126 of catheter 120 (e.g.) Figure 2A (As shown) can be inserted into the patient's body 160, and more specifically, can be inserted into the patient's heart 180 (also as shown) Figure 2A(As shown). The catheter 120 may include a handle 118, a shaft 122 having a proximal end 124 and a distal end 126, and one or more sensors (e.g., such as...) mounted within or on the shaft 122 of the catheter 120. Figure 2B (Sensors 150, 152, 154, 156, and 170 are shown). As used herein, "sensor 150" may refer to one or more sensors, as specifically described and as generally intended. Sensor 150 may include conduit electrodes and / or magnetic sensors. Figure 2A As shown, sensor 150 is located at the distal end 126 of shaft 122. Monitoring data from one or more sensors 150 is transmitted via shaft 122 to handle 118 and received by medical positioning system 140. As described in more detail below, impedance-based positioning systems utilize signals received from one or more electrodes (e.g., electrodes 152, 154, 170) to determine the position of the electrodes within the patient. Similarly, magnetic positioning systems utilize signals received from magnetic sensor 156 to determine the position of magnetic sensor 156 within the patient. Both impedance-based positioning system 136 and magnetic positioning system 138 can generate corresponding position estimates. ECU 144 receives impedance-based position estimates and magnetic-based position estimates (and in some embodiments, additional signals measured by one or more sensors located on conduit 120), and uses the received estimates to determine whether to operate in an impedance-based mode (in which the position of conduit 120 is visualized to display 142 based on the impedance-based position estimate) or in a magnetic-based mode (in which the position of conduit 120 is visualized to display 142 based on the magnetic-based position estimate).

[0047] The catheter 120 may also include other conventional components, such as, but not limited to, a temperature sensor, an additional sensor or electrode, an ablation element (e.g., an ablation tip electrode for delivering radiofrequency ablation energy, a high-intensity focused ultrasound ablation element, etc.), and corresponding conductors or leads.

[0048] The shaft 122 may be an elongated, tubular, flexible member for movement within the body 160. The shaft 122 supports (e.g., but not limited to) sensors and / or electrodes mounted thereon, such as sensor 150, associated conductors, and other electronics that may be used for signal processing and modulation. The shaft 122 may also allow the transport, delivery, and / or removal of fluids (including perfusion fluids, cryoablation fluids, and body fluids), drugs, and / or surgical instruments or devices. The shaft 122 may be made of conventional materials such as polyurethane and defines one or more lumens configured to receive and / or transport electrical conductors, fluids, or surgical instruments. The shaft 122 may be introduced into a blood vessel or other structure within the body 160 via a conventional inserter. Using methods known in the art, the shaft 122 can then be manipulated or guided through the body 160 to a desired location, such as the heart 180.

[0049] Sensors 150 mounted within or on the shaft 122 of catheter 120 may be provided for a variety of diagnostic and therapeutic purposes, including, but not limited to, electrophysiological studies, pacing, cardiac mapping, and ablation. One or more sensors 150 may be provided to perform localization or position sensing functions. More specifically, as described in more detail below, one or more sensors 150 may be localization sensors that provide information relating to the localization (e.g., position and orientation) of catheter 120 and its distal end 126 of shaft 122, particularly at a particular point in time. Thus, as catheter 120 moves along and / or around the surface of and / or within the structure of interest of heart 180, sensors 150 may be used to collect localization data points corresponding to other locations on and / or within the surface of the structure of interest. These localization data points may then be used for a variety of purposes, such as, but not limited to, constructing a surface model of the structure of interest. For clarity and illustration purposes, the following description will refer to catheter 120, wherein a single sensor 150 includes a localization sensor. It should be understood that, however, in other exemplary embodiments (which remain within the spirit and scope of this disclosure), catheter 120 may include more than one positioning sensor, as well as other sensors or electrodes configured to perform other diagnostic and / or therapeutic functions, such as being configured to determine the six degrees of freedom of the catheter. As will be described in more detail below, sensor 150 may include pairs of leads extending from its sensing element (e.g., a coil) that electrically couple sensor 150 to other components of system 100, such as, for example, medical positioning system 140.

[0050] Some embodiments of the medical positioning system 140 will be described below. The medical positioning system 140 may be provided with sensors 150 for determining the position and / or orientation of catheter 120, and thereby determining the position and / or orientation of the distal portion of catheter 120. The medical positioning system 140 may include a magnetic field-based system, such as, for example, the MediGuide™ system of MediGuide Ltd. (now owned by St. Jude Medical, Inc.), which is generally referred to in one or more of U.S. Patent Nos. 6,233,476, 7,197,354, and 7,386,339, the entire contents of which are incorporated herein by reference.

[0051] The medical positioning system 140 includes at least a portion of a magnetic field generator 130 for generating a magnetic field to track an object (e.g., the distal portion of catheter 120). The magnetic field generator 130 can generate a low-intensity magnetic field within and around the patient's chest cavity (e.g., a region of interest during cardiac surgery procedures), which can be defined in a three-dimensional space specifying a magnetic motion frame 132 (also referred to as the "region of interest"). As briefly described above, catheter 120 includes magnetic sensors (e.g., Figure 2B The magnetic sensor 150 (shown as magnetic sensor 156) detects one or more characteristics of a low-intensity magnetic field applied by the magnetic field generator 130 when positioned within the magnetic motion frame 132. Sensor 150 can be electrically / communicationally coupled to the processing circuitry of the medical positioning system 140. The signal received by the processing circuitry corresponds to the sensed characteristics of the magnetic field exposed to the sensor. In response to the detected signal, the processing circuitry calculates the three-dimensional position and / or orientation of sensor 150, and the input to the magnetic field generator 130. Therefore, the medical positioning system 140 is able to track each magnetic sensor 150 of catheter 120 in three-dimensional space in real time, thereby enabling real-time tracking of catheter 120.

[0052] In this exemplary embodiment, the magnetic field-based positioning system 138 uses a magnetic field to detect the position and orientation of the catheter 120 within the body 160. System 138 may include the GMPS system provided by MediGuide, Inc., which has been generally shown and described, for example, in U.S. Patent No. 7,386,339 entitled “Medical Imaging and Navigation System,” the entire contents of which are incorporated herein by reference, as if fully set forth herein. In this system, a magnetic field generator 130 with three orthogonally arranged coils (not shown) can be used to create a magnetic field within the body 160. The generator can be configured to control the strength, direction, and frequency of the field. The magnetic field generator 130 may be located above or below the patient (e.g., below the patient table) or other suitable location. The coils generate the magnetic field and acquire current or voltage measurements from one or more position sensors 150 (e.g., magnetic sensors 156) associated with the catheter 120. The measured current or voltage decreases as the distance between the sensor and the coil increases, thereby allowing determination of the sensor's position in a second coordinate system 164 of system 138.

[0053] A magnetic field generator 130 may be located below a patient examination table 168, between an X-ray source 172 and the patient examination table 168. For example, the magnetic field generator 130 may be coupled to the patient examination table 168. The magnetic field generator 130 may be a mobile device placed on the patient's chest and used to generate a magnetic field to track an object. Aspects of this disclosure may relate to the magnetic field generator 130, which includes one or more sensors on various sides of a magnetic motion frame 132 of the patient 160. Magnetic field distortions within (and outside) the magnetic motion frame (region of interest) can be canceled, for example, by generating opposing magnetic fields on opposite sides of the distorted object, thereby canceling the magnetic field at the location of the distorted object. Magnetic field emitters may be positioned at various locations around the magnetic motion frame 132 to create different magnetic field directions, thereby reducing eddy currents from the distorted object.

[0054] The medical positioning system 140 includes at least one or more surface patch electrodes 134 for generating an electric field to track an object (e.g., the distal portion of catheter 120). The surface patch electrodes 134 can generate an electric / impedance field within and around the patient's body 160. The surface patch electrodes 134 can be positioned on and / or around the patient's body 160 to generate an impedance-based coordinate system. Catheter 120 may include a positioning sensor 150 comprising electrodes or electrode pairs (e.g., electrodes 152 and 154) that, when the sensor 150 is positioned within the patient's body 160, detect one or more characteristics of the electric field applied by the surface patch electrodes 134. In an exemplary embodiment, sensor 150 includes electrodes or electrode pairs that can be electrically / communicationally coupled to processing circuitry of the medical positioning system 140. Signals received by the processing circuitry correspond to perceived characteristics of the electric field exposed by the electrodes. In response to the detected signals, the processing circuitry calculates the three-dimensional position and / or orientation of sensor 150, and the input to the surface patch electrodes. Therefore, the medical positioning system 140 is able to track each electrode sensor 150 of the catheter 120 in three-dimensional space in real time, and thus track the catheter 120 in real time.

[0055] System 100 may include an electric field-based positioning system 136, a magnetic field-based positioning system 138, a display 142, and an electronic control unit (ECU) 144. Each exemplary system component will be further described below.

[0056] An electric field-based positioning system 136 (also known as an "impedance-based positioning system") may be provided to determine the position and orientation of catheter 120 and similar devices within body 160. System 136 may include, for example, the ENSITE NAVX system sold by St. Jude Medical Supplies, Inc. of St. Paul, Minnesota, which has been described, for example, in U.S. Patent No. 7,263,397 entitled "Method and Apparatus for Catheter Navigation and Location Mapping in the Heart," the entire contents of which are incorporated herein by reference as if fully set forth herein. System 136 operates on the principle that, when a low-amplitude current signal passes through the chest, body 160 acts as a voltage divider (or potential generator or rheostat) such that the potential measured at one or more electrodes 150 (e.g., electrodes 152, 154) on catheter 120 can be used to determine electrode 150 using Ohm's law and the relative position of a reference electrode (e.g., in the coronary sinus), and thus the position of catheter 120 relative to external patch electrode pair 134.

[0057] The impedance-based positioning system 136 may also include multiple pairs of patch electrodes 134 provided to generate electrical signals for determining the position of catheter 120 in a first three-dimensional coordinate system 162. Electrodes 134 may also be used to generate impedance-based position data about tissues of the patient's body 160. To create electric fields along specific axes within the body 160, patch electrodes are placed on opposing surfaces of the body 160 (e.g., the chest and back, the left and right sides of the chest, and the neck and legs), generally forming orthogonal x, y, and z axes. A reference electrode / patch (not shown) is typically placed near the stomach to provide a reference value and serve as the origin of the first coordinate system 162 for the navigation system. A sinusoidal current may be driven through each pair of patch electrodes 134 by an electrical signal generator 146 to acquire voltage measurements from one or more position sensors 150 associated with catheter 120 (e.g., electrodes 152, 154 or tip electrodes 170 located near the distal end 126 of catheter shaft 122). The measured voltage is a function of the distance between the position sensor and the patch electrode. The measured voltage is compared with the potential at the reference electrode to determine the position of the position sensor in the navigation system's coordinate system 162.

[0058] Display 142 is provided to convey information to a physician to assist in diagnosis and treatment. Display 142 may include one or more conventional computer monitors or other display devices. Display 142 may present a graphical user interface (GUI) to the physician. The GUI may include various information, including, for example, geometric images of tissue / heart 180, electrophysiological data associated with heart 180, graphs showing changes in voltage levels of various sensors 150 over time, and images of catheters 120 and other medical devices, as well as relevant information indicating the position of catheters 120 and other devices relative to the patient's body 160.

[0059] ECU 144 provides a method for controlling the operation of various components of system 100, including catheter 120, an electrical signal generator 146, a switch 148 of an electric field-based positioning system 136, and a magnetic generator 130 of a magnetic field-based positioning system 138. For example, ECU 144 can be configured by appropriate software to provide control signals to switch 148, thereby sequentially coupling patch electrode pairs 134 to signal generator 146. Excitation of each pair of electrodes 134 generates electromagnetic fields within body 160 and in regions of interest, such as the heart. ECU 144 may also provide a method for determining the geometry of tissue 180, the electrophysiological characteristics of tissue 180, and the position and orientation of catheter 120 relative to tissue 180 and body 160. ECU 144 also provides a method for generating display signals for controlling display 142. The ECU 144 shown in the figure represents any processing scheme, such as, for example, a single device processor, multiple device processors (e.g., coprocessors, master / slave processors, etc.), distributed processing across multiple components / systems, system-on-a-chip (SoC) devices, etc.

[0060] Figure 2A -B is a schematic diagram of the patient's heart 180, in which a sensor-enabled catheter 120 is inserted. (See diagram below.) Figure 2A As shown, the shaft 122 of the catheter 120 extends into the left ventricle of the patient's heart 180; however, it is foreseeable that the shaft 122 of the catheter 120 may also be located in or around other chambers or blood vessels of the patient's heart 180.

[0061] The sensor 150 of catheter 120 may include an electrode 170 at its distal tip, configured to acquire positioning data and / or tissue data. The sensor 150 of catheter 120 may include catheter electrode pairs 152 and 154, configured to acquire positioning data and / or tissue data; specifically, electrodes 152 and 154 may be configured to detect one or more characteristics of an impedance field / electric field applied by surface patch electrode 134. The sensor 150 of catheter 120 may include a magnetic sensor 156 configured to detect one or more characteristics of a magnetic field applied by magnetic field generator 130. The magnetic sensor 156 may include a coil configured to generate an electrical signal in response to the presence of a magnetic field.

[0062] Figure 3A flowchart of a method 300 for collecting cardiac medical information using a catheter and presenting it to a physician, according to some embodiments, is shown. At step 302, a first signal and a second signal are received from one or more sensors located on the catheter. The first signal may include impedance-based position and / or orientation data, and the second signal may include magnetic position and / or orientation data. In some embodiments, the first signal is received from one or more electrodes located distal to the catheter, and the second signal is received from a magnetic sensor located distal to the catheter. The catheter electrodes used in step 302 may include… Figure 1-2B One or more of the catheter electrodes 152, 154, and 170 are shown. Catheter electrodes 152, 154, and 170 can generate electrical signals in response to movement through or placement in an electric field (or impedance field) generated by one or more surface patch electrodes 134. That is, this first signal can be correlated with signals received with respect to an impedance-based positioning system. Alternatively, the first signal received from one or more catheter electrodes may be independent of impedance-based positioning measurements. For example, the first signal received from the catheter electrodes may include voltage, current, impedance, or bipolar electrical complex impedance (BECI). This first signal can be generated in response to a signal driven between electrode pairs (e.g., catheter electrodes 152 and 154, or between catheter electrode 152 and surface patch electrode 134). For example, the bipolar electrical complex impedance (BECI) value can be measured by driving an AC signal between electrode pairs, where at least one electrode of the electrode pair is located on a catheter. As described in more detail below, the BECI value can be used to determine whether a catheter is located within the body.

[0063] The magnetic sensor used in step 302 may include Figure 2B The magnetic sensor 156 is shown. The magnetic sensor 156 can generate an electrical signal in response to movement through or within a magnetic field generated by the magnetic field generator 130. A second signal received from the magnetic sensor may include voltage, current, or other electrical signals. The second signal received from the magnetic sensor may be related to the position and / or orientation of the sensor within the magnetic motion frame 132. Since the second signal is generated by the movement of the sensor through the magnetic field, the position and / or orientation of the magnetic sensor may be referred to as "magnetic-based" positioning / navigation.

[0064] At step 306, a first navigation mode is generated. The first navigation mode (or "impedance-based navigation mode") is generated by receiving a first electrical signal from an electrode and analyzing that first electrical signal using ECU 144 or a processor. The first electrical signal can be converted into an impedance-based position point in a first coordinate system. The first navigation mode can track the position of one or more conduit electrodes (e.g., electrodes 152, 154) over multiple time intervals and store the data in ECU 144. The first navigation mode can measure the output of one or more patch electrodes (e.g., patch electrode 134).

[0065] At step 308, a second navigation mode is generated. The second navigation mode (or "magnetism-based navigation mode") is generated by receiving a second electrical signal from a magnetic sensor and analyzing that signal using ECU 144 or a processor. This second electrical signal can be converted into a magnetically based position point in a second coordinate system. The second navigation mode can track the position of one or more magnetic sensors (e.g., magnetic sensor 156) over multiple time intervals and store the data within ECU 144. The second navigation mode can measure the output of a magnetic field generator (e.g., magnetic field generator 130).

[0066] At step 310, it is determined whether the catheter is inside the patient's body. Generally, the term "inside the patient's body" means that the catheter is inserted into the patient's body at any point on the patient's body (e.g., leg, chest, arm) (i.e., through the skin surface). Determining whether the catheter is inside the patient's body may include analyzing a first signal and / or a second signal received from the catheter electrodes and / or magnetic sensors, as described in step 302. Figure 4An example of a method for determining whether a catheter is located within a patient's body using a first signal is provided. The location of the catheter within the body can be determined using only the first signal (e.g., a signal received from one or more catheter electrodes). The first signal can be generated in response to an impedance-based positioning system, where electrodes are used to sense an impedance field generated by multiple surface patch electrodes. The presence (or absence) of the detected impedance field can be used to determine whether the catheter is located within the body, where the detection of the presence of the impedance field indicates that the catheter is located within the body. Alternatively, the location of the catheter within the body can be determined using actual location information determined from the first signal (as part of an impedance-based positioning system). Alternatively, instead of utilizing the impedance field generated by an impedance-based positioning system, the first signal can be generated in response to a signal generated between electrode pairs (at least one of which is located on the catheter) by driving a signal between the respective electrode pairs. For example, an alternating current (AC) signal can be provided between the respective electrode pairs, and a resulting bipolar electrode complex impedance (BECI) value, representing the first signal, can be calculated based on the measured response. The BECI value can be used to determine whether a catheter is located inside the body, where the measured BECI value represents whether one or more catheter electrodes are in contact with the blood pool (i.e., inside the body) or in contact with air (and therefore not inside the body).

[0067] If it is determined in step 310 that the catheter is not inside the patient's body, then at step 330, the display will be prevented from outputting navigation mode. In other words, if the catheter is not inside the patient's body, the display (e.g., Figure 3 The display 142 will not show the catheter position and orientation. Impedance-based and / or magnet-based positioning systems may receive input from the catheter and may generate output indicating the catheter position, but the ECU 144 prevents these outputs from being displayed on the display 142. After determining in step 310 that the catheter is not inside the patient's body, the corresponding positioning system (e.g., impedance-based positioning, magnet-based positioning) cannot be activated. Thus, the display 142 will not unintentionally indicate to the user that the catheter is inside the body. Steps 302 and 310 can be repeated until it is determined that the catheter is inside the patient's body. This loop can be time-limited, i.e., steps 302 and 310 can be repeated every t seconds, where t is an adjustable time value between 0.1 seconds and 10 seconds.

[0068] If it is determined in step 310 that the catheter is inside the patient's body, then in step 320 it is determined whether the catheter is within the magnetic motion frame (e.g., Figure 1 Within the magnetic motion frame 132 shown. Determining whether the catheter is within the magnetic motion frame may include analyzing received signals from the catheter electrodes and / or magnetic sensors, as described in step 302. Methods 500, 502, and 504 (e.g.) can be used. Figure 5A-C (as shown) determines whether the catheter is within the magnetic motion frame. Determining whether the catheter is within the magnetic motion frame depends on the catheter's defined position, compared to determining whether the catheter is inside the patient's body in step 310 (which may be based, for example, detecting whether the catheter electrode is located within the blood pool). Thus, impedance-based positioning based on signals received from the catheter electrode and / or magnetic positioning based on signals received from the magnetic sensor can be used to determine whether the catheter is within the magnetic motion frame. Impedance-based positioning can be used to determine whether the catheter is within the magnetic motion frame. Magnetic positioning can be used to determine whether the catheter is within the magnetic motion frame. A combination of impedance-based positioning and magnetic positioning can be used to determine whether the catheter is within the magnetic motion frame (e.g., both must indicate that the catheter is within the magnetic motion frame).

[0069] If it is determined that the catheter is inside the patient's body (step 310) but not within the magnetic motion frame (step 320), then in step 340, the catheter's position is displayed on the display using an impedance-based navigation mode. In step 340, impedance-based data on the catheter's position and orientation (i.e., data from the first signal) can be output to the display 142. For example, the first signal can be received from the catheter electrode, and impedance-based position and / or orientation data can be calculated based on this first signal. The impedance-based position and / or orientation data can then be output to the display 142 to provide a visual representation of the catheter's position and / or orientation within the patient's body. A magnetic positioning system can receive a second signal from a magnetic sensor and can generate magnetic-based position and / or orientation information, but this information will not be output to the display 142 as long as the system is operating in impedance-based navigation mode.

[0070] After determining in step 340 that an impedance-based navigation mode will be output to display 142, the process continues to monitor whether the catheter is located inside the patient's body in steps 302 and 310. That is, the process can continue at steps 302 and 310 to receive a first signal and / or a second signal to determine whether the catheter is located inside the patient's body, as described above.

[0071] If it is determined that the catheter is inside the patient's body (step 310) and within the magnetic motion frame (step 320), then in step 350, the position of the catheter is displayed on the display 142 using a magnetic-based navigation mode. In step 350, magnetic-based data on the catheter's position and orientation (i.e., data from a second signal) can be output to the display 142. For example, the second signal can be received from a magnetic sensor, and magnetic-based position and / or orientation data can be calculated based on this second signal. The magnetic-based position and / or orientation data can then be output to the display 142 to provide a visual representation of the catheter's position and / or orientation within the patient's body. An impedance-based positioning system can receive a first signal from one or more catheter electrodes and can generate impedance-based position and / or orientation information, but this information is not output to the display 142 as long as the system is operating in magnetic-based navigation mode. In step 350, when operating within the magnetic motion frame, both magnetic-based positioning and impedance-based positioning can be utilized. For example, position and / or orientation can be output as an aggregation or combination of magnetic-based positioning and impedance-based positioning.

[0072] Having determined that the catheter is within the magnetic motion frame, and displaying its position using a magnetic-based navigation mode at step 350, the process continues at step 302 by receiving impedance-based and magnetic-based position data from the catheter. First and second navigation modes are continuously generated (steps 306 and 308), and the process continues to determine whether the catheter is inside the patient's body (step 310) and whether it is within the motion frame (step 320). Therefore, method 300 may include a feedback loop after steps 330, 340, and 350 to continuously update steps 310 and / or 320 and generate output accordingly. For example, if the physician moves the catheter out of the magnetic motion frame, the visualization / navigation system may automatically revert to the impedance-based navigation mode. Method 300 may include switching between the impedance-based and magnetic-based navigation modes as the catheter moves across the boundaries of the magnetic motion frame. Therefore, method 300 may allow physicians to switch between a first and second navigation mode in a single study (i.e., without resetting the navigation system).

[0073] In one example, when a physician moves a catheter from an incision site (e.g., the femoral or radial artery) to the heart, the catheter may initially be determined to be inside the patient's body (step 310) and outside the magnetic motion frame (320), and method 300 may proceed to step 340. At some point, the catheter may cross the boundary into the magnetic motion frame, and thus, the catheter may be inside the patient's body (step 310) and inside the magnetic motion frame (320), and the method may proceed to step 350. Due to the automatic feedback loop in method 300, operation in impedance-based navigation mode and / or magnetic-based navigation mode can proceed automatically, requiring feedback and / or notification from the physician. Or in other words, the physician can switch from impedance-based navigation mode to magnetic-based navigation mode without stopping the procedure. In some embodiments, the determinations at steps 310 and 320 may prompt the physician to change the navigation mode. For example, if the catheter moves from inside the patient's body and outside the magnetic motion frame (impedance-based navigation mode) to inside the patient's body and inside the magnetic motion frame, the display may include prompts (e.g., instructions or questions) to guide the physician to select magnetic-based navigation mode. Therefore, according to some embodiments, switching from one navigation mode to another may be susceptible to the influence of doctor input.

[0074] In some embodiments, determining that the catheter is within the magnetic motion frame (step 320) may also determine that the catheter is inside the patient's body (step 310). For example, if the magnetic motion frame is completely contained within the patient's body, i.e., only around the patient's heart and / or does not extend outside the patient's chest cavity, then determining that the catheter is within the magnetic motion frame will necessarily be related to the catheter being inside the patient's body.

[0075] Figure 4 Method 400 for determining whether a catheter is located inside a patient's body is shown. Method 300 (see...) Figure 3 Step 310 of method 400 can be used. In step 410, an electrical signal is provided as input to one or more catheter electrodes. This electrical signal can be provided to a single catheter electrode (e.g., a monopole having a return path provided via a surface patch electrode). Alternatively, the electrical signal can be provided between a pair of catheter electrodes (bipole). For example, the electrode pair may include... Figure 2B The catheter electrodes 152 and 154 are shown. The electrical signal can be an AC signal. The frequency of the AC signal can be within a given range (e.g., 16-19 kHz) and can be unique for each pair of catheter electrodes. A signal generator (not shown), controlled by ECU 144, can be configured to drive a unique sine wave through the electrode pair.

[0076] At step 420, an electrical signal is measured in response to the signal provided in step 410. For example, the voltage between the electrode pairs can be measured, and the measured voltage is transmitted to ECU 144. At step 430, bipolar complex impedance (BECI) is calculated based on the response measured in step 420 for each catheter electrode and / or electrode pair. BECI data can be acquired and preprocessed by an amplifier device, and the BECI measurements for each electrode can be arranged as cosine / sine pairs. The BECI measurement of an electrode depends on the conductivity of the medium in which the electrode is in contact. For example, since blood pools and / or tissues provide a lower impedance path between electrodes, the BECI generated in contact with blood pools or tissues is relatively lower than that in contact with air.

[0077] Method 400 may include step 450, determining whether the BECI indicates contact with a blood pool and / or tissue. Step 450 may include comparing a received BECI value to a threshold. For example, if the received BECI value exceeds the threshold, the BECI value may indicate contact between the electrode and a blood pool or patient tissue. Conversely, if the BECI value is below the threshold, the BECI value may indicate contact between the electrode and air or a catheter sheath. If the BECI value indicates contact between the electrode and a blood pool or tissue, step 460 may generate an output indicating that the catheter is inside the patient's body. If the BECI value does not indicate contact between the electrode and a blood pool or tissue, step 470 may generate an output indicating that the catheter is outside the patient's body. The threshold may be a pre-characterized static constant or a dynamically characterized value established through baseline steps (preferably one baseline step per study).

[0078] Method 400 may include a set of rules to determine whether the catheter is outside the patient's body. For example, if the measurement value of one electrode in the electrode pair is higher than a threshold (e.g., 0.5e...),... 3 If the BECI measurement is greater than X%, then both electrodes forming the BECI pair are outside the body. If more than X% of the electrodes are outside the body, then the entire catheter can be determined to be outside the body, where X is an optional value between 10 and 90. If the distal electrode pair includes a BECI measurement indicating that the catheter is outside the body, then the entire catheter can be determined to be outside the body.

[0079] Step 310 of method 300 may include determining the position of the catheter based on a received first signal (i.e., according to impedance-based position and orientation data). If the position of the catheter is determined to be within the patient's body according to the impedance-based position and orientation data, method 300 may proceed to step 320. A physician may manually (i.e., via a user interface on ECU 144 or display 142) determine whether the catheter is within the patient's body.

[0080] Figure 5A -C illustrates a flowchart of the method for determining whether a catheter is within a magnetic motion frame. (See diagram below.) Figure 5AAs shown, method 500 includes step 510, generating a magnetic field. This magnetic field can be generated by... Figure 1 The magnetic field generator 130 shown generates a magnetic field to form a magnetic motion frame (e.g., magnetic motion frame 132).

[0081] Method 500 may include step 520, receiving an electrical signal generated by a magnetic sensor in response to a magnetic field generated in step 510. The magnetic sensor may include... Figure 2B The magnetic sensor 156 is shown. The magnetic sensor may include a coil configured to generate a current (or electrical signal) when moved through a generated magnetic field. The ECU 144 may measure the electrical signal from the magnetic sensor. At step 530, the electrical signal from the magnetic sensor is used to generate an estimate of the magnetic sensor's position and / or orientation in the magnetic field. For example, based on the received electrical signal, the ECU 144 may be configured to calculate the magnetic-based position and orientation of the magnetic sensor. The position of the magnetic sensor relative to the conduit may be known; therefore, the conduit position and orientation can be determined via the received electrical signal.

[0082] In step 540, the measured position and orientation of the magnetic sensor are compared with the boundary of the magnetic motion frame. The magnetic motion frame can be defined as a cuboid, which serves as a coordinate system with coordinates X and Y. min To X max Y min To Y max and Z min To Z max The patient's heart is surrounded by a three-dimensional space. Alternatively, the magnetic motion frame can be defined by other geometries and / or coordinate systems. Step 540 may include comparing the measured position with the coordinates of the magnetic motion frame.

[0083] At step 550, it is determined whether the measurement position of the magnetic sensor is within the motion frame. If the measurement position is within the three-dimensional coordinates of the magnetic motion frame, method 500 can proceed to step 560, outputting a determination that the conduit is within the motion frame. If the measurement position is outside the three-dimensional coordinates of the magnetic motion frame, method 500 can proceed to step 570, outputting a determination that the conduit is outside the motion frame.

[0084] like Figure 5B As shown, at step 515, a voltage / impedance field is generated. This voltage / impedance field can be generated by generating a voltage across a surface patch electrode placed on the patient's body. At step 525, an electrical signal is measured at one or more catheter electrodes. The catheter electrodes may include... Figure 2B The catheter electrodes 152 and 154 are shown. The electrical signal may include voltage, current, impedance, or other electrical signals.

[0085] At step 535, the position of the electrodes within the patient's body is determined using electrical signals. For example, based on the received electrical signals, ECU 144 can be configured to calculate the impedance-based position of the catheter electrodes. The positions of two or more catheter electrodes, combined with geometric / shape information associated with the catheter, can be used to determine the catheter's orientation and position. The position and orientation of the catheter electrodes, combined with information about the position of the magnetic sensor relative to the catheter electrodes, can be used to determine the impedance-based position of the magnetic sensor, which differs from the magnetic-based position of the magnetic sensor determined based on a signal generated in response to a magnetic field.

[0086] At step 545, the measured position of the catheter electrode and / or magnetic sensor is compared with the boundary of the magnetic motion frame. The magnetic motion frame can be defined as a cuboid that surrounds the patient's heart as a three-dimensional space with coordinates. At step 555, it is determined whether the measured position of the catheter electrode and / or magnetic sensor is within the magnetic motion frame. If the measured position is within the three-dimensional coordinates of the magnetic motion frame, an output is generated at step 565 indicating that the catheter electrode and / or magnetic sensor is located within the motion frame. If the measured position of the catheter electrode and / or magnetic sensor is determined to be outside the three-dimensional coordinates of the magnetic motion frame, an output is generated at step 575 indicating that the catheter is located outside the motion frame.

[0087] Figure 5C A method 504 for determining whether a catheter is within a magnetic motion frame is shown. Method 504 includes elements of methods 500 and 502, namely, determining whether a catheter is within a magnetic motion frame by using both magnetically based positioning (steps 510, 520, 530, 540) and impedance-based positioning (steps 515, 525, 535, 545).

[0088] Method 504 may include step 580, using magnetically based catheter localization and impedance-based catheter localization to determine a confidence interval. For example, using magnetically based localization (steps 510, 520, 530, 540), the method can determine the location of the catheter and assign a magnetically based confidence value to that location (i.e., based on magnetically based localization, the system has X% confidence that the catheter is within the motion frame). Using impedance-based localization (steps 515, 525, 535, 545), the method can determine the location of the catheter and assign an impedance-based confidence value to that location (i.e., based on impedance-based localization, the system has Y% confidence that the catheter is within the motion frame). Method 504 may utilize a weighted combination of the magnetically based confidence value and the impedance-based confidence value to determine the confidence interval (step 580).

[0089] Step 590 compares the calculated confidence interval with a threshold to determine whether the catheter is within the motion frame. If the calculated confidence interval is greater than the threshold, method 504 proceeds to step 592 and determines that the catheter is within the motion frame. If the calculated confidence interval is less than the threshold, method 504 proceeds to step 575 and determines that the catheter is outside the motion frame.

[0090] The above detailed description includes reference to the accompanying drawings, which form a part of the detailed description. The detailed description should be read with reference to the accompanying drawings. The drawings illustrate, by way of example, specific ways of practicing the present apparatus, system, and method. These apparatuses, systems, and methods are also referred to herein as "examples".

[0091] The detailed description is intended to be illustrative and not limiting. For example, the examples above (or one or more features or components therein) may be used in combination with each other. Other embodiments may be used by those skilled in the art upon review of the detailed description and the drawings. Furthermore, various features or components have been or may be combined together to simplify this disclosure. This should not be construed as any unclaimed disclosed feature being essential to any claim. Rather, the subject matter of the invention may lie in fewer than all the features of the disclosed device, system, or method. Therefore, the following claims are incorporated herein by reference, each example being treated as a separate aspect:

[0092] In Example 1, a method for collecting cardiac medical information using a medical device and presenting it to a physician includes: receiving impedance-based position data from electrodes; generating a first navigation pattern for visualizing the medical device using the impedance-based position data; receiving magnetic-based position data from a magnetic sensor; generating a second navigation pattern for visualizing the medical device using the magnetic-based position data; determining whether the medical device is within a magnetic motion frame generated by a magnetic field generator; and determining whether the medical device is within the magnetic motion frame using one or more of the magnetic-based position data and the impedance-based position data. The method includes: outputting the first navigation pattern to a display when the medical device is outside the magnetic motion frame; and outputting the second navigation pattern to a display when the medical device is inside the magnetic motion frame.

[0093] In Example 2, the method of Example 1 may optionally be configured to include switching between a first navigation mode and a second navigation mode as the conduit moves across the boundary of the magnetic motion frame.

[0094] In Example 3, the methods of Example 1 and / or 2 are optionally configured such that the first navigation mode includes receiving a first electrical signal measured by the electrodes. The first electrical signal is analyzed using the ECU. The first electrical signal is converted into a first position point in an impedance coordinate system.

[0095] In Example 4, the methods of any of the examples in Examples 1-3 can optionally be configured such that the second navigation mode includes receiving a second electrical signal generated by a magnetic sensor in response to an external magnetic field. This second electrical signal is analyzed using an ECU. The second electrical signal is then converted into a second position point in a magnetic coordinate system.

[0096] In Example 5, the methods of any of the examples in Examples 1-4 may optionally be configured such that determining whether a medical device is within a magnetic motion frame includes comparing a second location point of a magnetic sensor with the boundary of the magnetic motion frame.

[0097] In Example 6, the methods of any of the examples in Examples 1-5 may optionally be configured such that determining whether a medical device is within a magnetic motion frame includes comparing a first position point of the electrode with the boundary of the magnetic motion frame.

[0098] In Example 7, the methods of any of the examples in Examples 1-6 may optionally be configured such that determining whether a medical device is within a magnetic motion frame includes comparing a second position point of a magnetic sensor with the boundary of the magnetic motion frame and comparing a first position point of an electrode with the boundary of the magnetic motion frame.

[0099] In Example 8, the methods of any of the examples in Examples 1-7 may optionally be configured to include determining whether the medical device is inside the patient's body. When the medical device is outside the patient's body, neither the first navigation mode nor the second navigation mode is output to the display.

[0100] In Example 9, the methods of any of the examples in Examples 1-8 may optionally be configured such that determining whether a medical device is in a patient's body includes: driving an electrical signal through a first electrode and receiving a bipolar complex impedance at a second electrode. This bipolar complex impedance is then compared to a threshold.

[0101] In Example 10, the methods of any of the examples in Examples 1-9 can optionally be configured such that the transition between the first navigation mode and the second navigation mode occurs in a single study, and includes a model transformation. The first position point in the impedance-based coordinate system is transformed into a magnetic-based coordinate system.

[0102] In Example 11, the methods of any of the examples in Examples 1-10 can optionally be configured such that when a magnetic sensor is detected in the magnetic motion frame, the transition from the first navigation mode to the second navigation mode occurs automatically in a single study.

[0103] In Example 12, the methods of any of the examples in Examples 1-11 can optionally be configured such that when a magnetic sensor is detected in the magnetic motion frame, the physician is prompted to switch from the first navigation mode to the second navigation mode in a single study.

[0104] In Example 13, the methods of any of the examples in Examples 1-12 can optionally be configured such that the first navigation mode and the second navigation mode continuously and simultaneously calculate the magnetic sensor position and the electrode position, regardless of whether the first navigation mode or the second navigation mode is output to the display.

[0105] In Example 14, the methods of any of the examples in Examples 1-13 can optionally be configured such that the magnetic motion box is a cuboid defining a three-dimensional (3D) coordinate system, which is configured to surround the patient's heart.

[0106] In Example 15, a medical imaging and navigation system includes a medical device, a pair of surface-mount electrodes, a magnetic field generating component, a display, and a processor. The medical device includes device electrodes and a magnetic sensor. The surface-mount electrode pair is positionable on a patient. The surface-mount electrode pair is configured to generate an electric field within the patient's body. A first electrical signal is measured on the device electrodes due to the generated electric field. The magnetic field generating component is positioned near the patient. The magnetic field generating component generates a magnetic field within a motion frame. A second electrical signal is measured on the magnetic sensor due to the generated magnetic field. The processor receives the first electrical signal from the device electrodes and determines a first position of the device electrodes based on the first electrical signal. The processor stores the first position in a first dataset. The processor receives the second electrical signal from the magnetic sensor and determines a second position of the magnetic sensor based on the second electrical signal. The processor stores the second position in a second dataset. The processor uses the first dataset to construct an impedance-based mapping study and uses the second dataset to construct a magnetic-based mapping study. The processor selectively outputs either the impedance-based mapping study or the magnetic-based mapping study to the display based on the position of the medical device within the patient's body. The processor is configured to switch from impedance-based calibration studies to magnetism-based calibration studies in a single study.

[0107] In Example 16, the system of Example 15 is optionally configured such that when the medical device is inside the patient's body and outside the motion frame, the processor is configured to output impedance-based calibration studies to the display.

[0108] In Example 17, the system of any of the examples in Examples 15-16 may optionally be configured such that when the medical device is inside the patient's body and within the motion frame, the processor is configured to output a magnetically based mapping study to the display.

[0109] In Example 18, the system of any of the examples in Examples 15-17 may optionally be configured such that the processor determines whether a medical device is in the patient’s body by measuring the bipolar complex impedance and comparing the bipolar complex impedance with a threshold.

[0110] In Example 19, the system of any of the examples in Examples 15-18 can optionally be configured such that the threshold is a dynamic feature value established through a baseline step.

[0111] In Example 20, the system of any of the examples in Examples 15-19 is optionally configured such that the display includes a user interface configured to allow a physician to select between a first navigation mode and a second navigation mode in a single study.

[0112] Certain terms used in this patent document refer to features or components. Different people may use different names to refer to the same feature or component. This patent document is not intended to distinguish between components or features with different names but the same function.

[0113] The scope of this device, system, and method should be determined by reference to the appended claims and the full scope of their equivalents. In the appended claims, the terms "comprising" and "wherein" are used as concise English equivalents of the terms "including" and "therein," respectively. Furthermore, in the following claims, the terms "comprising" and "including" are open-ended; that is, any device, system, or method that includes features or components other than those listed after the term in a claim shall still be considered to fall within the scope of that claim. Additionally, in the following claims, the terms "first," "second," and "third," etc., are used merely as labels and are not intended to impose a quantitative requirement on their contents.

[0114] An abstract is provided to allow readers to quickly determine the nature of the technical disclosure. The submission of an abstract is based on the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Claims

1. A method for collecting cardiac medical information using a medical device and presenting it to a physician, the method comprising: Receive impedance-based position data from the electrodes; A first navigation pattern for visualization of medical devices is generated using impedance-based location data. Receive magnetic-based position data from a magnetic sensor; A second navigation mode for visualization of medical devices is generated using the magnetic-based location data. One or more of the magnetic-based position data and the impedance-based position data are used to determine whether the medical device is within the magnetic motion frame generated by the magnetic field generator; as well as When the medical device is outside the magnetic motion frame, it outputs the first navigation mode to the display; and when the medical device is inside the magnetic motion frame, it outputs the second navigation mode to the display.

2. The method of claim 1, further comprising switching between the first navigation mode and the second navigation mode when the medical device moves across the boundary of the magnetic motion frame.

3. The method according to claim 1 or 2, wherein, Generating the first navigation mode includes: Receive a first electrical signal measured by the electrodes; The first electrical signal is analyzed using an electronic control unit (ECU); and The first electrical signal is converted into a first position point in an impedance-based coordinate system.

4. The method according to claims 1-3, wherein, Generating the second navigation mode includes: Receives a second electrical signal generated by the magnetic sensor in response to an external magnetic field; The second electrical signal is analyzed using the ECU; and The second electrical signal is converted into a second position point in a magnetically based coordinate system.

5. The method according to claim 4, wherein, Determining whether the medical device is within the magnetic motion frame includes: The second position point of the magnetic sensor is compared with the boundary of the magnetic motion frame.

6. The method according to claim 4 or 5, wherein, Determining whether the medical device is within the magnetic motion frame includes: The first position point of the electrode is compared with the boundary of the magnetic motion frame.

7. The method according to any one of claims 1-6, further comprising determining whether the medical device is inside the patient's body, wherein, When the medical device is outside the patient's body, neither the first navigation mode nor the second navigation mode is output to the display.

8. The method according to claim 7, wherein, Determine whether the medical device is present in the patient's body: The driving electrical signal passes through the first electrode; Measure the voltage signal on the second electrode; Calculate the bipolar complex impedance using the measured voltage signal; and The bipolar complex impedance is compared with a threshold.

9. The method according to any one of claims 4-6, wherein, The transition between the first navigation mode and the second navigation mode occurs within a single study and includes a model transformation, wherein the first position point in the impedance-based coordinate system is transformed into the magnetic-based coordinate system.

10. The method according to claim 9, wherein, When the magnetic sensor is detected in the magnetic motion frame, the transition from the first navigation mode to the second navigation mode occurs automatically in the single study.

11. The method according to claim 9 or 10, wherein, When the magnetic sensor is detected in the magnetic motion frame, the doctor is prompted to switch from the first navigation mode to the second navigation mode in the single study.

12. The method according to any one of claims 1-11, wherein, Regardless of whether the first navigation mode or the second navigation mode is output to the display, the first navigation mode and the second navigation mode continuously and simultaneously calculate the magnetic sensor position and the electrode position.

13. The method according to any one of claims 1-12, wherein, The magnetic motion frame is a cuboid that defines a three-dimensional (3D) coordinate system and is configured to surround the patient's heart.

14. A medical imaging and navigation system, comprising: Medical devices, including device electrodes and magnetic sensors; A pair of surface patch electrodes capable of being positioned on a patient, the pair of surface patch electrodes being configured to generate an electric field within the patient's body, wherein a first electrical signal is measured on the device electrodes due to the generated electric field; A magnetic field generating component positioned near the patient is configured to generate a magnetic field within a magnetic motion frame, wherein a second electrical signal is measured on the magnetic sensor due to the generated magnetic field. monitor; A processor is configured to receive a first electrical signal from a device electrode and determine a first position point of the device electrode based on the first electrical signal, the processor being configured to store the first position in a first dataset; wherein, the processor is also configured to receive a second electrical signal from a magnetic sensor and determine a second position point of the magnetic sensor based on the second electrical signal, the processor being configured to store the second position in a second dataset. The processor uses the first dataset to construct an impedance-based calibration study and the second dataset to construct a magnetism-based calibration study. The processor selectively outputs either the impedance-based mapping study or the magneto-based mapping study to the display based on the location of the medical device within the patient's body; wherein the processor is configured to switch from the impedance-based mapping study to the magneto-based mapping study in a single study.

15. The medical imaging and navigation system according to claim 14, wherein, When the medical device is inside the patient's body and outside the magnetic motion frame, the processor is configured to output impedance-based calibration studies to the display.

16. The medical imaging and navigation system according to claim 14 or 15, wherein, When the medical device is inside the patient's body and within the magnetic motion frame, the processor is configured to output the magnetic-based mapping study to the display.

17. The medical imaging and navigation system according to any one of claims 14-16, wherein, The processor determines whether the medical device is inside the patient's body by measuring the bipolar impedance and comparing the bipolar impedance to a threshold.

18. The medical imaging and navigation system according to claim 17, wherein, The threshold is a dynamic feature value established through a baseline step.

19. The medical imaging and navigation system according to any one of claims 14-18, wherein, The display is a user display, which optionally includes a user interface configured to allow physicians to select between a first navigation mode and a second navigation mode in a single study.

Images